Even a two-hour exposure to air pollution mainly in the form of traffic exhaust can wipe out the positive health benefits of walking on the lungs and hearts of the elderly researchers have warned. The findings showed that even short-term exposure to traffic exhaust can have negative effects on both healthy people as well as those with pre-existing cardio respiratory conditions such as chronic obstructive pulmonary disease (COPD) or coronary disease. The study comes at a time when north India is facing a serious crisis due to rising levels of pollution. This adds to the growing body of evidence showing